WO2006001281A1 - Seal ring - Google Patents

Abstract

A seal ring which eliminates direct contact with a side wall plane is provided by widely forming an oil film on a side plane which slides on the side wall plane on a non hermetically sealed fluid side of an annular groove. On a side plane (12) of a seal ring (1), an oil groove (16) is provided. The oil groove widens in an outer diameter direction and a circumference direction from the deepest part (17) on an inner circumference plane (14) and gradually becomes shallow in the outer diameter direction and the circumference direction from the deepest part (17), as it advances in a rotating direction of a rotating axis.

Description

 Specification

 Sino-Reling Technology

 TECHNICAL FIELD [0001] The present invention relates to a seal ring that is used for shaft seals of automatic transmissions of automobiles, various hydraulic devices, and pneumatic devices, and seals an annular gap between a rotating shaft and a housing disposed in an annular groove. It is. Background art

 [0002] Seal rings are used as seals for rotation and oscillation. As shown in FIG. 9, this seal ring 1 is disposed in an annular groove 3 provided around the outer peripheral surface of the rotary shaft 2, and is pressed into close contact with the outer peripheral surface 11 against the inner wall of the knowing 4 by hydraulic pressure P. In addition, the side surface 12 on the anti-oil side (U in FIG. 9) is pressed against the side wall surface of the annular groove 3 and sealed. In Fig. 9, O indicates the oil side. At this time, the seal ring 1 itself does not rotate, but the rotating shaft 2 rotates (arrow J in FIG. 9). Therefore, the outer peripheral surface 11 of the seal ring 1 does not slide closely against the housing 4 (see FIG. 9). The portion 12 on the opposite oil side slides with the side wall surface of the annular groove 3 of the rotating shaft 2 (portion L in FIG. 9). Here, since the side surface 12 on the anti-oil side of the seal ring 1 and the side wall surface of the annular groove 3 slide through the oil film, the seal ring 1 and the side wall surface are in direct contact with each other in a preferable use state. Not much.

 [0003] However, when high-pressure usage conditions and the surface roughness of the side wall surface are rough, as shown in FIG. 10, at the point N where the roughness is larger than the thickness of the oil film M, the anti-oil side of the seal ring 1 The side surface 12 and the side wall surface of the annular groove 3 are in direct contact with each other, and wear is caused by sliding.

[0004] As a countermeasure against direct contact between the side surface 12 of the seal ring 1 opposite to the oil side and the side wall surface of the annular groove 3, as shown in FIG. It is considered that an oil groove 20 capable of introducing an oil film on the surface 12 on the side opposite to the oil side 2 is provided in the seal ring 1 when 2 rotates. Fig. 11 (a) is a view taken along the arrow G in Fig. 11 (b), and Fig. 11 (b) is a cross section taken along the line H-H in Fig. 11 (a). The oil groove 20 shown in FIG. 11 has inclined surface portions 21 and 22 on both sides in the circumferential direction of the deep portion, and the oil introduced into the oil groove 20 is inclined surface portions 21 and 2 by the rotation of the rotating shaft 2. The oil film is transferred from 2 to the side surface 12 to form an oil film, and the seal ring 1 is separated from the side wall surface of the annular groove 3 by buoyancy due to the pressure of the oil film.

[0005] However, in the case of Patent Document 1, the hydraulic pressure for pressing the seal ring 1 is larger than the buoyancy due to the pressure of the oil film. In this case, the seal ring 1 is in contact with the side wall surface, which is not a countermeasure. . Specifically, in Patent Document 1, as shown in FIG. 12, the range of the oil film that produces buoyancy formed by the oil groove 20 is limited to the Y ′ portion. For this reason, if the hydraulic pressure that presses the seal ring 1 is greater than the buoyancy due to the oil film pressure, even if the Y 'part where the oil film is formed is protected by the oil film, the part other than the Y' part (Ζ 'part) Has no oil film protection. Therefore, the portion other than the Y ′ portion (Ζ ′ portion) on the side surface 12 on the oil-off side of the seal ring 1 comes into direct contact with the side wall surface of the annular groove 3 of the rotating shaft 2. In this case, the parts other than the Y 'part (the heel' part) are worn away by sliding.

 Patent Document 1: Japanese Patent Laid-Open No. 09-210211

 Disclosure of the invention

 Problems to be solved by the invention

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to form an oil film widely on the side surface of the annular groove that slides with the side wall surface on the anti-sealing fluid side, and to directly contact the side wall surface. It is to provide a seal ring that eliminates the possibility of contact.

 Means for solving the problem

In order to achieve the above object, the present invention adopts the following configuration. That is, it is attached to an annular groove provided around the outer peripheral surface of the rotating shaft, the outer peripheral surface is brought into close contact with the inner wall of the housing through which the rotating shaft is inserted, and the side surface is slidable on the side wall surface of the annular groove on the anti-sealing fluid side. A seal ring that tightly seals and seals an annular gap between the rotating shaft and the housing,

Opened to the inner peripheral surface on the side surface of the seal ring, and the deepest force on the inner peripheral surface side extends in the outer diameter direction and the circumferential direction as it advances in the rotation direction of the rotating shaft, and from the deepest portion to the outer diameter direction and It is a seal ring characterized by providing grooves that gradually become shallower in the circumferential direction. The invention's effect

 [0008] According to the present invention, an oil film can be widely formed on the side surface sliding with the side wall surface on the anti-sealing fluid side of the annular groove, eliminating direct contact with the side wall surface, reducing wear, Excellent durability.

 Brief Description of Drawings

FIG. 1 is a partial perspective view of a seal ring according to an embodiment.

 FIG. 2 is a side external view of a seal ring according to an embodiment.

 FIG. 3 is a cross-sectional view of an oil groove portion of the seal ring according to the embodiment.

 FIG. 4 is an external view of the inner peripheral surface of the oil groove portion of the seal ring according to the embodiment.

 FIG. 5 is a view showing an oil groove forming range of the seal ring according to the embodiment.

 FIG. 6 is a partial perspective view of a seal ring according to another example of the embodiment.

 FIG. 7 is a partial perspective view of a seal ring according to another example of the embodiment.

 FIG. 8 is a side external view of a seal ring according to another example of the embodiment.

 FIG. 9 is a half cross-sectional view showing a seal ring mounted state.

 FIG. 10 is a half cross-sectional view showing a case where the surface of the annular groove in which the seal ring is mounted has roughness unevenness.

 FIG. 11 is a view of an oil groove portion of a conventional seal ring, (a) is an arrow view and (b) is a cross-sectional view.

 FIG. 12 is a diagram showing an oil groove forming range of a conventional seal ring.

 Explanation of symbols

[0010] 1 Seal ring

 2 Rotating axis

 3 Annular groove

 4 Housing

 11 Outer surface

 12 Anti-oil side

13 Oil side 16 Oil groove

 16 '2nd oil groove

 17 deepest

 18 Oil groove side wall

 19 Bottom of oil groove

 BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments will be described with reference to the drawings. FIG. 1 is a partial perspective view of a seal ring according to an embodiment. FIG. 2 is a side external view of the seal ring according to the embodiment. 3 is a cross-sectional view of the oil groove portion of the seal ring according to the embodiment, and is a cross-sectional view taken along the line AA of FIG. FIG. 4 is an external view of the inner peripheral surface of the seal ring according to the embodiment, and is a view as seen from the direction of arrow B in FIG.

 In the present embodiment, the seal ring 1 has a quadrangular cross section, an outer peripheral surface 11 in close contact with the inner wall of the housing 4 facing the annular groove 3 of the rotating shaft 2, and the annular groove of the rotating shaft 2. 3 Side surface 12 on the opposite side of the oil that slides in close contact with the wall surface, side surface 13 on the oil side opposite to the side surface 12 (O in FIG. 9), and annular groove 3 on the rotating shaft 2 And an inner peripheral surface 14 facing the groove bottom side.

 As shown in FIG. 9, the seal ring 1 is mounted in an annular groove 3 provided around the outer peripheral surface of the rotary shaft 2 and is hydraulically connected to the nosing 4 inserted through the rotary shaft 2 by hydraulic pressure. The outer peripheral surface 1 1 is pressed against the inner wall and brought into close contact, and the side surface 12 is pressed against the side wall surface of the annular groove 3 on the anti-oil side (anti-sealing fluid side) so as to be slidably brought into contact with each other. Seal the annular gap between them. As will be described later, in this embodiment, moderate leakage is allowed rather than oil leakage being completely prevented.

 Here, the oil as the sealing fluid is, for example, a lubricating oil, and refers to ATF (Automatic Transmission Fluid) when used in an automobile transmission.

Further, as shown in FIG. 2, the seal ring 1 is provided with a separation portion 15 at one place in the circumferential direction. The separating portion 15 is provided to facilitate the mounting work when the seal ring 1 is mounted. The separation unit 15 is a special step cut. Special step cut has two steps A step-shaped cut appears on both the side surface 12 and the side surface 13. With this special step cut, the amount of leakage can be reduced, and even if the seal ring 1 expands or contracts due to a change in the ambient temperature, the gap can be suitably prevented from correspondingly increasing.

 [0016] In the seal ring 1 of the present embodiment as described above, the side surface 12 is provided with a plurality of oil grooves (grooves) 16 that are scattered throughout the entire circumference.

 [0017] The oil groove 16 opens to the inner peripheral surface 14, has a deepest portion (deepest portion) 17 at one end on the inner peripheral surface 14 side, and advances toward the rotation direction of the rotary shaft 2 toward the inner peripheral surface 14 side. It spreads from the deepest part 17 in the outer diameter direction and the circumferential direction, and gradually becomes shallower from the deepest part 17 in the outer diameter direction and the circumferential direction.

 [0018] Specifically, the shape of the opening of the oil groove 16 with respect to the side surface 12 of the seal ring 1 is a substantially curved parallelogram, as shown in FIG. 1 to 4, the oil groove 16 opens on the inner peripheral surface 14 (1 in FIG. 4), and the rotational direction of the rotary shaft 2 starts from the deepest portion 17 on the inner peripheral surface 14 side. The oil groove side wall 18 is extended in the outer diameter direction while curving from the deepest portion 17 and the opening on the inner peripheral surface 14 side is expanded in the circumferential direction. The oil groove bottom surface 19 of the oil groove 16 has an inclined surface that becomes shallower as the distance from the deepest portion 17 (either in the outer diameter direction or the circumferential direction) is increased.

 [0019] In addition, the edge of the oil groove 16 with the side surface 12 of the seal ring 1 (C, D, E portion in FIG. 2) and the boundary between the side surface 12 of the seal ring 1 and the inner peripheral surface 14 (FIG. 2). The F part) is rounded to R. As a result, the oil can be smoothly introduced to the side 12 on the anti-oil side of the seal ring 1 without damaging the oil at the corners.

 [0020] In the side surface 12 having such an oil groove 16, oil is introduced from the opening on the inner peripheral surface 14 side of the oil groove 16 when the rotary shaft 2 rotates. By the rotation of the rotating shaft 2, the deepest portion 17 side force of the oil groove 16 also runs up the inclined oil groove bottom surface 19 and flows toward the shallow part spreading in the outer diameter direction and the circumferential direction. Further, the shallow partial force of the oil groove 16 further spreads to the surface of the side surface 12 without forming oil at the peripheral edge portion (C, D, E portion) of the oil groove 16 that becomes R, forming an oil film.

FIG. 5 is a diagram showing an oil film formation range of the seal ring 1 according to the embodiment. Shown in Figure 5 As described above, an oil film is formed between the sliding side surface 12 and the side wall surface of the annular groove 3 in the outer diameter side of the oil groove 16 and in a wide range (Y portion) in the circumferential direction. In particular, the angle of the part where oil is introduced from the oil groove 16 to the side surface 12 is R, and the oil groove bottom surface 19 of the oil groove 16 has a slope that gradually becomes shallower with respect to the oil entering direction. Following movement due to the viscosity of the oil when rotating is performed well, and it is possible to easily form a thick oil film over a wide range of the side surface 12. Of the oil film, in the outer diameter side region of the side surface 12 of the seal ring 1, the side wall surface of the annular groove 3 is lost, leading to a gap between the rotating shaft 2 and the housing 4, so that leakage to the anti-oil side occurs. However, this leakage is acceptable.

 [0022] Here, the dimensions of the oil groove 16 are as follows. In the AT seal ring 1 of a passenger car, the depth of the deepest portion 17 of the oil groove 16 is 0.02 mm to l. Omm, and the oil groove of the oil groove 16 Inclination angle of bottom surface 19: 1 ° to 45 °, circumferential length of oil groove 16: 0.2 mm to 5. Omm, peripheral edge of oil groove 16: R: R 0.1 mm to R5. Set in the range of Omm Is done. Further, the number of the oil grooves 16 is provided so that an oil film is formed over the entire circumference of the side surface 12 of the seal ring 1 in consideration of the circumferential length of the seal ring 1, the operating pressure, and the sliding speed.

 [0023] In order to form such an oil groove 16, seal ring 1 is made of a resin material such as ultra-high molecular weight polyethylene, PPS, PEEK, etc., and a resin containing a filler as necessary. It is manufactured by injection molding using materials.

 In the embodiment described above, the oil groove 16 is provided on the side surface 12 of the seal ring 1 so that the oil in the oil groove 16 spreads to the side surface 12 of the seal ring 1 when the rotary shaft 2 rotates. Move it thickly. As a result, an oil film can be formed almost entirely on the side 12 of the seal ring 1 opposite to the oil side, eliminating direct contact with the side wall of the annular groove 3 on the side 12 and reducing wear. The seal ring 1 can be excellent in durability.

 [0025] In addition, since the corner of the boundary between the peripheral edge of the oil groove 16 and the side surface 12 and the inner peripheral surface 14 is rounded to R, oil is not applied to the side surface 12 from the oil groove 16 without scraping oil at the corner. Since it can be introduced, a wide and thick oil film can be formed on the side surface 12.

[0026] In the above embodiment, the opening shape of the side surface 12 side force of the oil groove 16 is a force that was a substantially curved parallelogram shape. Expands from the deepest part 17 on the peripheral surface 14 side in the outer diameter direction and the circumferential direction, and extends from the deepest part 17 A triangular shape as shown in FIG. 6 or a fan shape as shown in FIG. 7 is also included in the scope of the present invention as long as it gradually becomes shallower in the radial direction and the circumferential direction.

 [0027] Further, in the seal ring 1 of the above embodiment, the rotation direction of the rotation shaft 2 is limited to one direction. However, in the case of the rotation shaft 2 in which the rotation direction is reversed, As shown in FIG. 8, an oil groove 16 and a second oil groove (second groove) 16 ′ that is a mirror image are preferably provided. As the second oil groove 16 ′ advances in the reverse rotation direction of the rotary shaft 2, the deepest part force on the inner peripheral surface 14 side also spreads in the outer diameter direction and the circumferential direction, and gradually from the deepest part in the outer diameter direction and the circumferential direction. It's shallow. As described above, when the oil groove 16 is provided with the second oil groove 16 ′ that is a mirror image, the seal ring to which the present invention is applied can be used even when the rotation direction of the rotary shaft 2 rotates forward and backward. .

 [0028] Further, these seal rings 1 are provided with an oil groove 16 and a second oil groove 16 'formed on both of the two sides 12 and 13 of the seal ring 1 so that the seal ring 1 can be reversed. Good to be. As a result, it is possible to prevent erroneous assembly of the seal ring 1.

Claims

The scope of the claims  [1] Mounted in an annular groove provided around the outer peripheral surface of the rotary shaft, the outer peripheral surface is brought into close contact with the inner wall of the housing through which the rotary shaft is inserted, and the side surface slides on the side wall surface of the annular groove on the anti-sealing fluid side A seal ring that seals an annular gap between the rotating shaft and the housing in close contact with each other;  Opened to the inner peripheral surface on the side surface of the seal ring, and the deepest force on the inner peripheral surface side extends in the outer diameter direction and the circumferential direction as it advances in the rotation direction of the rotating shaft, and from the deepest portion to the outer diameter direction and A seal ring characterized by providing grooves that gradually become shallower in the circumferential direction.  [2] The seal ring according to claim 1, wherein corners of a peripheral portion of the groove with a side surface of the seal ring and corners of a boundary between the side surface of the seal ring and the inner peripheral surface are rounded.  [3] The sheathing according to claim 1 or 2, wherein the groove and a second groove having a mirror image are provided on a side surface of the seal ring.